Reconstruct motion path features
This example shows a couple of different scenarios involving the reconstruction of motion path features to geological times.
See also
See also
Exported reconstructed motion paths to a file
In this example we reconstruct motion path features and export the results to a Shapefile.
See also
Create a motion path feature and Query a motion path feature
Sample code
import pygplates
# Load one or more rotation files into a rotation model.
rotation_model = pygplates.RotationModel('rotations.rot')
# Load some motion path features.
motion_path_features = pygplates.FeatureCollection('motion_path_features.gpml')
# Reconstruct features to this geological time.
reconstruction_time = 50
# The filename of the exported reconstructed motion paths.
# It's a shapefile called 'motion_path_output_50Ma.shp'.
export_filename = 'motion_path_output_{0}Ma.shp'.format(reconstruction_time)
# Reconstruct the motion paths to the reconstruction time and export them to a shapefile.
pygplates.reconstruct(motion_path_features, rotation_model, export_filename, reconstruction_time,
reconstruct_type=pygplates.ReconstructType.motion_path)
Details
The rotations are loaded from a rotation file into a pygplates.RotationModel.
rotation_model = pygplates.RotationModel('rotations.rot')
The motion path features are loaded into a pygplates.FeatureCollection.
motion_path_features = pygplates.FeatureCollection('motion_path_features.gpml')
The motion path features will be reconstructed to their 50Ma positions.
reconstruction_time = 50
All motion path features are reconstructed to 50Ma using
pygplates.reconstruct().We specify we only want to reconstruct motion path features by specifying
pygplates.ReconstructType.motion_path for the reconstruct_type argument.We specify a filename to export the reconstructed geometries to.
pygplates.reconstruct(motion_path_features, rotation_model, export_filename, reconstruction_time,
reconstruct_type=pygplates.ReconstructType.motion_path)
Output
We should now have a file called motion_path_output_50Ma.shp containing the motion paths
reconstructed to their 50Ma positions.
Query a reconstructed motion path
In this example we print out the point locations in a reconstructed motion path.
Sample code
import pygplates
# Specify two (lat/lon) seed points on the present-day African coastline.
seed_points = pygplates.MultiPointOnSphere(
[
(-19, 12.5),
(-28, 15.7)
])
# A list of times to sample the motion path - from 0 to 90Ma in 1My intervals.
times = range(0, 91, 1)
# Create a motion path feature.
motion_path_feature = pygplates.Feature.create_motion_path(
seed_points,
times,
valid_time=(max(times), min(times)),
relative_plate=201,
reconstruction_plate_id=701)
# Load one or more rotation files into a rotation model.
rotation_model = pygplates.RotationModel('rotations.rot')
# Reconstruct features to this geological time.
reconstruction_time = 50
# Reconstruct the motion path feature to the reconstruction time.
reconstructed_motion_paths = []
pygplates.reconstruct(motion_path_feature, rotation_model, reconstructed_motion_paths, reconstruction_time,
reconstruct_type=pygplates.ReconstructType.motion_path)
# Iterate over all reconstructed motion paths.
# There will be two (one for each seed point).
for reconstructed_motion_path in reconstructed_motion_paths:
# Print the motion path plate IDs.
print 'Motion path: %d relative to %d at %fMa' % (
reconstructed_motion_path.get_feature().get_reconstruction_plate_id(),
reconstructed_motion_path.get_feature().get_relative_plate(),
reconstruction_time)
# Print the reconstructed seed point location.
print ' reconstructed seed point: lat: %f, lon: %f' % reconstructed_motion_path.get_reconstructed_seed_point().to_lat_lon()
motion_path_times = reconstructed_motion_path.get_feature().get_times()
# Iterate over the points in the motion path.
for point_index, point in enumerate(reconstructed_motion_path.get_motion_path()):
lat, lon = point.to_lat_lon()
# The first point in the path is the oldest and the last point is the youngest.
# So we need to start at the last time and work our way backwards.
time = motion_path_times[-1-point_index]
# Print the point location and the time associated with it.
print ' time: %f, lat: %f, lon: %f' % (time, lat, lon)
Details
The first part of this example comes from Create a motion path feature.
It creates a motion path feature specifying the seed point locations that each motion path emanates
from as well as a list of times to plot points in the path.
seed_points = pygplates.MultiPointOnSphere([(-19, 12.5), (-28, 15.7)])
times = range(0, 91, 1)
motion_path_feature = pygplates.Feature.create_motion_path(
seed_points,
times,
valid_time=(max(times), min(times)),
relative_plate=201,
reconstruction_plate_id=701)
The rotations are loaded from a rotation file into a pygplates.RotationModel.
rotation_model = pygplates.RotationModel('rotations.rot')
The features will be reconstructed to their 50Ma positions.
reconstruction_time = 50
The motion path feature is reconstructed to 50Ma using
pygplates.reconstruct().We specify a
list for reconstructed_motion_paths instead of a filename so that we
can query the reconstructed motion paths easily.We also specify we only want to reconstruct motion path features by specifying
pygplates.ReconstructType.motion_path for the reconstruct_type argument.reconstructed_motion_paths = []
pygplates.reconstruct(motion_path_feature, rotation_model, reconstructed_motion_paths, reconstruction_time,
reconstruct_type=pygplates.ReconstructType.motion_path)
We iterate over the points in the
reconstructed motion path
and print each point location and its associated time.The first point in the path is the oldest and the last point is the youngest.
So we need to start at the last (oldest) time and work our way backwards.
The last sample is at index
-1 and point_index starts at zero.
So our time indices are -1, -2, etc, which means last sample, then second last sample, etc.for point_index, point in enumerate(reconstructed_motion_path.get_motion_path()):
lat, lon = point.to_lat_lon()
time = motion_path_times[-1-point_index]
print ' time: %f, lat: %f, lon: %f' % (time, lat, lon)
Output
Our time range is 90Ma to 0Ma, but since the reconstruction time is 50Ma the output is only from 90Ma to 50Ma.
Motion path: 701 relative to 201 at 50.000000Ma
reconstructed seed point: lat: -26.580350, lon: 5.008040
time: 90.000000, lat: -31.198775, lon: -13.837430
time: 89.000000, lat: -30.982356, lon: -13.166848
time: 88.000000, lat: -30.759877, lon: -12.500510
time: 87.000000, lat: -30.531408, lon: -11.838481
time: 86.000000, lat: -30.297018, lon: -11.180823
time: 85.000000, lat: -30.056777, lon: -10.527593
time: 84.000000, lat: -29.810756, lon: -9.878842
time: 83.000000, lat: -29.621610, lon: -9.269242
time: 82.000000, lat: -29.491452, lon: -8.696601
time: 81.000000, lat: -29.358411, lon: -8.125578
time: 80.000000, lat: -29.222508, lon: -7.556197
time: 79.000000, lat: -29.083766, lon: -6.988478
time: 78.000000, lat: -28.942205, lon: -6.422443
time: 77.000000, lat: -28.797848, lon: -5.858112
time: 76.000000, lat: -28.650717, lon: -5.295502
time: 75.000000, lat: -28.500836, lon: -4.734632
time: 74.000000, lat: -28.348227, lon: -4.175519
time: 73.000000, lat: -28.192913, lon: -3.618178
time: 72.000000, lat: -28.034918, lon: -3.062625
time: 71.000000, lat: -27.874264, lon: -2.508873
time: 70.000000, lat: -27.710976, lon: -1.956935
time: 69.000000, lat: -27.545078, lon: -1.406823
time: 68.000000, lat: -27.376593, lon: -0.858549
time: 67.000000, lat: -27.293542, lon: -0.487339
time: 66.000000, lat: -27.247592, lon: -0.191647
time: 65.000000, lat: -27.201374, lon: 0.103869
time: 64.000000, lat: -27.154887, lon: 0.399209
time: 63.000000, lat: -27.108135, lon: 0.694373
time: 62.000000, lat: -27.061118, lon: 0.989360
time: 61.000000, lat: -27.013838, lon: 1.284170
time: 60.000000, lat: -26.966296, lon: 1.578802
time: 59.000000, lat: -26.918493, lon: 1.873257
time: 58.000000, lat: -26.870432, lon: 2.167534
time: 57.000000, lat: -26.822113, lon: 2.461632
time: 56.000000, lat: -26.773537, lon: 2.755552
time: 55.000000, lat: -26.740310, lon: 3.124328
time: 54.000000, lat: -26.708646, lon: 3.501316
time: 53.000000, lat: -26.676816, lon: 3.878182
time: 52.000000, lat: -26.644823, lon: 4.254924
time: 51.000000, lat: -26.612667, lon: 4.631544
time: 50.000000, lat: -26.580350, lon: 5.008040
Motion path: 701 relative to 201 at 50.000000Ma
reconstructed seed point: lat: -35.733432, lon: 7.829851
time: 90.000000, lat: -40.633500, lon: -12.902754
time: 89.000000, lat: -40.408039, lon: -12.104422
time: 88.000000, lat: -40.175428, lon: -11.312349
time: 87.000000, lat: -39.935768, lon: -10.526635
time: 86.000000, lat: -39.689160, lon: -9.747372
time: 85.000000, lat: -39.435708, lon: -8.974643
time: 84.000000, lat: -39.175516, lon: -8.208522
time: 83.000000, lat: -38.974541, lon: -7.507706
time: 82.000000, lat: -38.835379, lon: -6.868988
time: 81.000000, lat: -38.693052, lon: -6.232683
time: 80.000000, lat: -38.547588, lon: -5.598821
time: 79.000000, lat: -38.399018, lon: -4.967434
time: 78.000000, lat: -38.247371, lon: -4.338547
time: 77.000000, lat: -38.092678, lon: -3.712189
time: 76.000000, lat: -37.934970, lon: -3.088383
time: 75.000000, lat: -37.774279, lon: -2.467151
time: 74.000000, lat: -37.610634, lon: -1.848516
time: 73.000000, lat: -37.444068, lon: -1.232496
time: 72.000000, lat: -37.274612, lon: -0.619110
time: 71.000000, lat: -37.102299, lon: -0.008373
time: 70.000000, lat: -36.927159, lon: 0.599701
time: 69.000000, lat: -36.749226, lon: 1.205097
time: 68.000000, lat: -36.568530, lon: 1.807804
time: 67.000000, lat: -36.480099, lon: 2.202243
time: 66.000000, lat: -36.431745, lon: 2.507959
time: 65.000000, lat: -36.383124, lon: 2.813418
time: 64.000000, lat: -36.334239, lon: 3.118621
time: 63.000000, lat: -36.285091, lon: 3.423567
time: 62.000000, lat: -36.235682, lon: 3.728255
time: 61.000000, lat: -36.186013, lon: 4.032685
time: 60.000000, lat: -36.136086, lon: 4.336857
time: 59.000000, lat: -36.085903, lon: 4.640771
time: 58.000000, lat: -36.035465, lon: 4.944425
time: 57.000000, lat: -35.984774, lon: 5.247820
time: 56.000000, lat: -35.933832, lon: 5.550955
time: 55.000000, lat: -35.899285, lon: 5.924664
time: 54.000000, lat: -35.866424, lon: 6.306060
time: 53.000000, lat: -35.833407, lon: 6.687278
time: 52.000000, lat: -35.800235, lon: 7.068315
time: 51.000000, lat: -35.766909, lon: 7.449173
time: 50.000000, lat: -35.733432, lon: 7.829851
Note
The reconstructed seed point is the same position as the last point in a motion path.